Comment 13 for bug 1543778

Tested the above fix. I am unsure if this is solving the "root" issue of creating these broken db entries, but with an already broken environment it is still behaving badly

 (1) It still shows 20 unplaced units, that do not exist (these were not somehow cleaned up)
 (2) Hitting commit on a configuration change still creates machines for these units by default (though you can change it to leave unplaced)